[WrtCdEvrydy]

> There must be some interesting questions to solve, like how to avoid collision, or if they need error correction in case of wind, etc.

Yes, interestingly collisions aren't that difficult to avoid and wind can be countered but you can also simulate your show and tweak your "safety distance". You can actually see it in action in some drone shows when the lights go out... you'll the movements begin on the outer edge and then spread inwards minimizing the risk of collision.

RTK stations have been coming down in price little by little and are even commercially available from drone manufacturers like DJI for not a ridiculous amount of money.